General Motors Research Laboratories found in 1968 that no operating system, in existence or anticipated, was capable of supporting the demands of a large number of graphic terminals at a reasonable cost. Since a clear need for such a system was at hand, the Computer Science Department embarked on a project of hardware selection and software design and implementation. The total operating system is described here in five papers. They emphasize respectively l) the project background and major design principles, 2) the execution environment made available to application programs, 3) the implementation and status of privileged portions of the system, 4) the mechanism which handles interrupts and other system messages, and 5) the stand alone which performed the system initialization procedures.The resulting system had many desirable attributes, and thus convinced the designers, implementors, and users that the design as implemented was a useful and valuable one, even though rather unorthodox. The concepts embedded in the system and its components appear to be exportable to many other machine architectures, since they reflect the architecture of the host computer only in details, not in fundamental ways.One of the most important aspects of the design philosophy was that all portions of the system were designed together as mutually supportive components. This even extended to the programming language, whose execution environment was made the standard throughout the system, and was initialized for application programmers. This philosophy worked well and deserves wider attention.
The goals of the total MCTS System are stated in terms of capabilities which the customer tasks should be allowed to exercise. Treating these as premises, several derivative goals were deduced for the MCTS System, and these dictated the structure of the operating system and the nucleus. The deductions are exhibited, and the structure of the nucleus is derived. The body of this paper does not reference the hardware description of the computer on which the nucleus was implemented, and indeed the structure of the MCTS nucleus is philosophically hardware independent, except that it assumes a large scale processor with virtual memory address translation hardware, as is explained in the paper.The nucleus consists of three separate modules which cooperate to provide the environment in which the MCTS system operates. In that environment the individual components of the system execute as separate subtasks within a single task, the MCTS system task. They are written in a PL/I-like language; they are interruptible, yet each is run to its completion, thereby eliminating the need to synchronize between subtasks; they are suspended during requested I/O operations thus making I/O appear to be instantaneous; and their creation, modification, and checkout proved to be easy and fast.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.